Just make sure they are not playing any games with the price, since loaner miles are not supposed to effect you’re annual mileage.
Even if you are fine with the payment they give you I don’t think you want to pay for the salesman’s vacation.
What the dealer is telling you is correct. With GM loaner leases, the miles on the car do eat into mileage allotment you choose. I think it’s an eh deal because you have such a large amount due at signing. I mean it meets the 1% rule after accounting for the money due at signing, but $435 for a demo just isn’t amazing. I would try to get a bit more off the selling price. $4000 on a demo seems anemic
If it’s a “good” deal depends on his market. where are you? most dealer websites have discounted prices online. What is the discount on non-loaners in your area? if it’s 1k for others and 4k for this one, then you have a good deal. if it’s 3,800 usually then you don’t.